[영문]Social scientists who have estimated the relationship between a mother's work hours and the probability that her children care for themselves are often limited by cross-sectional data and use of a small number of control variables. This study uses the National Longitudinal Survey of Youth and a fixed effects logit model to ask if maternal work hours are related to the probability that adolescents spend some time at home alone after school. Results demonstrate that the relationship exists and is nonlinear: only the adolescents of mothers who work more than 30 hours per week are more likely to spend time after school with no adult present, compared with the adolescent children of mothers who are not working. This finding suggests that if social welfare policies encourage low-income mothers to work full-time, these policies may increase the probability that their adolescent children spend some time at home alone after school.